So after parking my car, I heard a strange loud noise In my engine bay. I turned off my car, and still heard the noise. I opened up the hood and found the air pump was making a loud noise similar to a running car. I disconnected the pump, and the sound stopped. No Check engine lights while pump is connected. Am I correct in assuming that the pump has gone bad and needs replacing? Anyone have a source for one that doesn't cost an arm, a leg, and a second student loan?

Thanks,
Kolme

Edit: Can someone move this to troubleshooting. Trying to use the iphone app and failed to place this in the correct thread.